1. Field of the Invention
The present invention relates to a clip used to fasten panels together, for example to attach interior trim panels of an automobile to metal body panels.
2. Description of the Prior Art
Many conventional clips have been designed to attach panels together. Particularly in the case of parts clips formed of synthetic resin, it is considered a matter of course to provide the clips with such a function. While synthetic resin clips are generally one-piece clips, there are also clips consisting of an assembly of a plurality of parts. Most clips are specially shaped depending on where they are to be used. Trim is used to provide a decorative surface covering. As such, when clips are used to attach trim it is desirable that the clips themselves are not visible on the surface. When large trim or other such panels are to be fitted by using a multiplicity of clips, to facilitate the task it is also desirable for the clips to be provisionally inserted in the panels beforehand. This also applies with respect to clips used to attach other parts, but the need is especially strong in the case of large panels, such as trim panels, which have numerous clips that are struck or pressed into engagement to thereby attach the panel.
Conventional clips used to attach trim panels include single-piece clips, and two-piece clips comprised of male and female members that are used to attach panels together by assembling the male and female members. In such a two-piece clip, a hollow body portion of the female member is inserted into a hole formed in a metal body panel where it is held by means of engaging portions provided on the peripheral surface of the body. A shaft extending perpendicularly from the underside of a head portion on the male member is inserted into a hole formed in the trim panel where it is maintained upright. The trim panel is then affixed to the body panel by assembling the male and female members by inserting the shaft into the cavity in the female member.
In the case of single-piece clips, the clip has a leg portion extending perpendicularly from the underside of a head portion shaped like a shallow saucer. The peripheral surface of the leg is provided with protruding or hooked shaped pieces for engagement. The two panels to be affixed are held together and the leg is inserted through holes formed in both panels and locked into engagement by means of the protruding or hooked shaped pieces, thereby clamping the panels together.
Among the advantages of the assembly type clip are that surface exposure can be avoided by affixing the head of the male member to the reverse side of the panel being affixed, the clip can be provisionally attached beforehand to the panel, and panels that have been fitted can be separated by disengaging the male and female members. Drawbacks of this type of clip include that they have to fitted in separate pieces, and that as each of the clips is comprised of two members, they are more costly than single-piece clips and more difficult in terms of product control.
Compared to assembly type clips, single-piece clips are cheaper to manufacture, and product control is also easier, as the clip is in the form of a single piece, which also makes them easier to handle. However, the difficulty of provisionally pre-attaching conventional single-piece clips to trim panels has led to a demand for an single-piece clip that offers improved provisional attachability.
The clip is inserted into a hole formed in a panel to be attached such as a trim panel and provisionally held there by means of protruding engaging portions or members provided on the clip leg, as described above. The trim panel is affixed to a body panel or the like by pushing the leg projecting from the hole in the trim panel into a hole in the body panel, whereby the engaging portions or members on the leg of the clip are moved into the hole in the body panel, thus affixing the panels together.
However, a problem occurs in that when the leg is pushed through into the hole in the panel, the fact that the protruding engaging portions or members are tapered to facilitate the insertion causes a loss of the provisional engagement. This results in a loss of the support needed to be able to insert and anchor the leg in the hole in the body panel. This can be circumvented by directly striking or pushing the head of each clip. However, in practice this can result in a loss of provisional engagement, causing clips to drop out of the panel.